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Finding the Fourth Proportional to 485.10, 669.20 and 307.76

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Solution

The fourth proportional to 485.10, 669.20 and 307.76 is: 424.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.10 : 669.20 = 307.76 : x
  2. Step 2: Convert to fraction form
    485.10/669.20 = 307.76/x
  3. Step 3: Cross multiply
    485.10x = 669.20 × 307.76
  4. Step 4: Simplify right side
    485.10x = 205,948.11
  5. Step 5: Solve for x
    x = 205,948.11/485.10
  6. Step 6: Final answer
    x = 424.55

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Double scale
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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.